Melanoma Flashcards
There are four main subtypes of melanoma. These are?
Superficial spreading
Nodular
Lentigo maligna
Acral lentiginous
Frequency of melanoma?
Superficial spreading - 70% of cases
Nodular - Second commonest
Lentigo maligna - Less common
Acral lentiginous - rare form
Superficial spreading typically affects?
Arms, legs, back and chest, young people
Nodular typically affects?
Sun exposed skin, middle-aged people
Lentigo maligna typically affects?
Chronically sun-exposed skin, older people
Acral lentiginous typically affects?
Nails, palms or soles, African Americans or Asians
Appearance of Superficial spreading?
A growing mole
Appearance of nodular?
Red or black lump or lump which bleeds or oozes
Appearance of Lentigo maligna?
A growing mole
Appearance of Acral lentiginous?
Subungual pigmentation (Hutchinson’s sign) or on palms or feet
There are other rare forms of melanoma including
desmoplastic melanoma, amelanotic melanoma, or melanoma arising in other parts of the body such as ocular melanoma.
The main diagnostic features (major criteria):
Change in size
Change in shape
Change in colour
Secondary features (minor criteria)
Diameter >= 7mm
Inflammation
Oozing or bleeding
Altered sensation
Mx melanoma?
Suspicious lesions should undergo excision biopsy. The lesion should be removed in completely as incision biopsy can make subsequent histopathological assessment difficult.
Once the diagnosis is confirmed the pathology report should be reviewed to determine whether further re-excision of margins is required
Further treatments such as sentinel lymph node mapping, isolated limb perfusion and block dissection of regional lymph node groups should be selectively applied.
Margins of excision?
Lesions 0-1mm thick: 1cm
Lesions 1-2mm thick: 1- 2cm (Depending upon site and pathological features)
Lesions 2-4mm: thick 2-3 cm (Depending upon site and pathological features)
Lesions >4 mm: thick 3cm
single most important factor in determining prognosis of patients with malignant melanoma?
invasion depth of a tumour (Breslow depth)
Breslow Thickness & Approximate 5 year survival?
< 0.75 m: 95-100%
0.76 - 1.50 mm: 80-96%
1.51 - 4 mm: 60-75%
> 4 mm: 50%
What is Lentigo maligna?
Lentigo maligna is a type of melanoma in-situ. It typically progresses slowly but may at some stage become invasive causing lentigo maligna melanoma.
Melanocytic naevi subtypes?
Congenital melanocytic naevi Junctional melanocytic naevi Compound naevi Spitz naevus Atypical naevus syndrome
naevi Increased risk of malignant transformation?
Congenital melanocytic naevi
increased risk greatest for large lesions
Describe Congenital melanocytic naevi
Typically appear at, or soon after, birth
Usually greater than 1cm diameter
Describe Junctional melanocytic naevi
Circular macules
May have heterogeneous colour even within same lesion
Most naevi of the palms, soles and mucous membranes are of this type
Describe Compound naevi
Domed pigmented nodules up to 1cm in diameter
Arise from junctional naevi, usually have uniform colour and are smooth
Describe Spitz naevus
Usually develop over a few months in children
May be pink or red in colour, most common on face and legs
May grow up to 1cm and growth can be rapid, this usually results in excision
Describe Atypical naevus syndrome
Atypical melanocytic naevi that may be autosomally dominantly inherited
Some individuals are at increased risk of melanoma (usually have mutations of CDKN2A gene
- Many people with atypical naevus syndrome AND a parent sibling with melanoma will develop melanoma
